PC shutting down

[Tringa]

Grateful for any advice or thoughts on a PC problem. Apologies for the long post.

Mrs Tringa's PC started to fail about couple of weeks ago. At switch on the fans would spin, the power light and HDD light on the front of the case would illuminate and after less than a minute it would shut down and attempt a restart which would have the same result. As the PC had, for a few months, intermittently BSOD'd with 'Page fault in a non paged area', I decided a rebuild was needed.

I replaced the motherboard, cpu, RAM and hard drive. The only bits from the old machine were the PSU, DVD and graphics card. I put it together, installed a copy of Windows 7 and for about a week it worked without a problem.

It then started to shut down for no obvious reason. Sometimes this would happen after a hour or so, but over the course of a few days the shut down was happening within about 10-15 seconds of switch on. During the time that the PC worked for an hour, there was no BSOD and the shut down was not temperature related – monitoring software showed the temperatures to be OK.

As this was a similar problem to that in the old PC I thought the PSU could be the cause, so replaced it this morning.

Now, when I switch on, all the fans (PSU, cpu, front, back and graphics card) spin for less than 10 seconds and then it shuts down.

The replacement PSU is an old one (I've had it for a few years but it has not been used) and of lower power(450w) than the original one(750w) but the replacement is a Corsair whereas original is a Win Power (not a name I'd heard of until this morning). I have unplugged the hard drive and the DVD to see if I could get it to POST, but no joy. The new components are nowhere near high spec – a dual core 3.2GHz G2130 cpu in a 1155 motherboard with 4 Gig of RAM, so I think 450w would be enough to get it started, at least.


Grateful for any advice. I'm a bit worried that a problem with the original PSU may have killed the new motherboard or the new hard drive.

Thanks

Dave

 

[neil_g]

is the CPU heat sink secure and thermal paste/pad in good order?

(assuming the PSU is a good one it shouldnt be under powered unless youre running a monster GPU and wouldnt really explain it working first off)

 

[ancient_mariner]

Some MoBos are fussy about power supply. I have a Gigabyte GA-EP45 DS3P, and there are warnings about not using an older spec of power supply on the Gigabyte site.

Probably worth going through and giving all the cards/connections a waggle too, just to make sure they're all seated.

 

[Carlh]

Does it power down when you're in the BIOS screen?. If not, doesn't sound like hardware. If its powering down AFTER windows has started, could be a virus.

 

[Gazamonk]

Dont want to sound obvious but if I read your post right, you have replaced everything but the graphics card. So why not stick in a cheap £15-20 card and see what happens or stick in an old pci card or some such, i bet you have one knockong around in a cupboard somewhere.
Does your new MB have built in Vga? Might be worth using that and removing your GPU card.

In a process of elimination its all you have left to try with regards hardware.

 

[Tringa]

Many thanks for the quick replies.

Neil, as far as I can see the cpu/heatsink is still OK. When the PC worked the cpu temps were about 31C. The graphics card is old and dates from before they needed an additional power supply so I'm sure it is not drawing much from the PSU.

Toni, interesting comment about Gigabyte boards. The new board is not the model you mentioned but it is a Gigabyte one. I have checked the seating of the components but I'll give them another check.

Carl, it does not get as far as the BIOS screen. I've just timed it - from switch on to it shutting down and the fans stopping is six seconds.

Gary, good idea. The motherboard does have onboard graphics so I'll give it a go.

Thanks all.

Dave

 

[NickH]

Sounds like it could be the mother board from what you describe. I know you have just replaced yours, but do you know its a good one, possibly could be faulty?

nick

 

[Gazamonk]

it does not get as far as the BIOS screen. I've just timed it - from switch on to it shutting down and the fans stopping is six seconds.

Sounds like the MB hardware or the Bios. What board do you have ? Can the Bios be reset by a jumper on the board ? If so then that is the 1st thing to try before pulling it apart again.

 

[LC2]

Check the motherboard isn't shorting against the case.

 

[Mikesphotaes]

I had something similar one, needed a new CPU when I thought it was (then bought) a new mobo

 

[neil_g]

Out of interest try reseating everything.. Memory, gpu (if installed) etc could be an iffy connection on a component stopping post. Also try combinations of individual memory sticks in different slots, could be faulty ram.

 

[Tringa]

Thanks for all the suggestions. I dismantled it completely, visually checked everything and put it all back together. I didn't bother with the graphics card and plugged the monitor into the motherboard. Unfortunately the result was the same.

I wondered if a faulty front panel switch could cause the problem so I disconnected all the front panel links - power switch, reset, HDD LED, etc., but again the same result. Just thought do the front panel switches have to be connected for a PC to work? Would me disconnecting them cause the effect I'm seeing?

Dave